bmi calculation formula imperial and metric

1def introduction_page():
2  print("Welcome to the BMI Calculator")
3  to_start = str(input("Y to start. N to exit"))
4  if to_start in ("Y","y"):
5    print("We will calculate now")
6    return main_page()
7  else:
8    print("exiting")
9
10
11def main_page():
12  found = False
13
14  while not found:
15    weight_store = float()
16    height_store = float()
17    user_weight = float(input("Please enter your weight(kg): "))
18    weight_confirm =  str(input("Y to confirm. N to re-enter"))
19    if weight_confirm in("y","Y"):
20      weight_store = weight_store + user_weight
21      while not found:
22        user_height = float(input("Please enter your height(m): "))
23        height_confirm = str(input("Y to confirm. N to re-enter"))
24        if height_confirm in ("Y","y"):
25          height_store = height_store + user_height
26          total_height = (height_store * height_store)
27          total_weight = (weight_store)
28          BMI = (total_weight / total_height)
29          print (int(BMI))
30          if (BMI < 18.5 or BMI <25) :
31            print("Normal Weight")
32            found = True
33          elif (BMI < 25 or BMI < 30):
34            print("Over-weight")
35            found = True
36          elif (BMI < 30 or BMI < 40):
37            print("Obesity")
38            found = True
39          else:
40            print("Morbid Obesity")
41            found = True
42        else:
43          print("Please re-enter")
44    else:
45      print("Please re-enter!")
46
47
48introduction_page()